The only time in my life when I experienced hair loss was when I was protein deficient -- it had nothing to do with the amount of carbs I was eating. At the moment, I'm not super-low carb; I'm grain-free and don't eat starchy fruits/vegetables, nor do I eat legumes. I get all my carbs from vegetables, nuts, fruits, and seeds -- in that order. I eat between 50 and 100 grams per day depending on how active I am. If anything, my hair is stronger and healthier now than it's ever been.
More likely than not, it has nothing to do with the carbs you're eating (or rather, not eating), but more to do with the rest of your diet. Make sure you're eating enough, and eating enough of the right things.